This invention relates to a method for producing a replaceable outer race for a ball and socket bearing, and more particularly, to an improved method for producing a filament wound one piece annular replaceable outer race for use on wide spherical balls.
Ball and socket bearings are designed for applications where both misaligning and oscillatory motions are present. These bearings are sometimes referred to as self-aligning bearings, and typically comprise a bearing with a spherical outer diameter, referred to as the ball, mounted within an opening, or the socket of a housing, thus forming the ball and socket bearing. The housing is frequently referred to as an outer race because the ball is mounted to rotate therein. In some installations the outer race is mounted within a separate outer housing such as a pillow block. In such outer race installations the outer race is in an intermediate position between the ball and the pillow block and thus may be referred to as an intermediate race instead of an outer race. However, for convenient reference, the term "outer race" will be used even though in some bearing assemblies the race may be located in an intermediate position. The outer race has an internal annular raceway integral therewith that is concave when viewed in section to mate with the outer surface of the spherical ball. The internal raceway and the outer spherical diameter of the ball must have a predetermined close tolerance fit to assure consistent bearing performance and long life.
It is known in the ball and socket bearing art to non-separably assemble the outer race to form an integral ball and socket bearing assembly. In integral ball and socket bearings the outer race is formed over a preformed spherical ball by molding, casting, filament winding or the like to complete the bearing assembly or the outer race may be first partially preformed, then placed on the spherical ball and finally forged, swaged or coined to complete the integral bearing assembly. When one element of an integral ball and socket bearing assembly fails the entire assembly is discarded.
It is also known to make a separable ball and socket bearing to permit replacement of either the spherical ball or the outer race. British Patent 554,879 issued Jul. 22, 1943 to Phillips and Power Aircraft Limited provides insertion flats on the spherical ball which allows it to be removably installed in the outer race. U.S. Pat. No. 3,116,539 issued Jan. 7, 1964 to Evans et al. and U.S. Pat. No. 4,848,934 issued Jul. 18, 1989 to Blakely et al. provide insertion slots in the outer race to permit installation and removal of the spherical ball. U.S. Pat. No. 3,888,554 issued Jun. 10, 1975 to McCloskey discloses a replacable spherical ball that includes at least three spherical interlocked segments to permit its removal and installation in the outer race.
Annular outer races for use in ball and socket bearings are normally produced by casting machining, or permanently fabricated on the ball in some way, for example, by filament winding, forging or swaging, which makes their production expensive. Requirements for lining a concave internal raceway of an outer race with a self-lubricating material adds to manufacturing costs and to the difficulty of producing an annular outer race wherein the integrity of the bond between the outer race and self-lubricating material is strong enough to insure that the outer race is durable under heavy duty rough service.